A collection of similar features. More...

Inheritance diagram for Geo::OGR::Layer:

Collaboration diagram for Geo::OGR::Layer:

Public Member Functions
public method	AlterFieldDefn (scalar name, hash params)

public list	Capabilities ()

public method	Clip (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	CommitTransaction ()

public method	CreateFeature (scalar feature)

public method	CreateField (hash params)

public method	DataSource ()

public method	Dataset ()

public method	DeleteFeature (scalar fid)

public method	DeleteField (scalar field)

public method	Erase (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	ForFeatures (scalar code, scalar in_place)

public method	ForGeometries (scalar code, scalar in_place)

public scalar	GeometryType (scalar field)

public Geo::OGR::DataSource	GetDataSource ()

public Geo::OGR::FeatureDefn	GetDefn ()

public list	GetExtent (scalar force=1)

public scalar	GetFIDColumn ()

public Geo::OGR::Feature	GetFeature (scalar fid)

public scalar	GetFeatureCount (scalar force=1)

public scalar	GetFeaturesRead ()

public hash	GetFieldDefn (scalar name)

public list	GetFieldNames ()

public scalar	GetName ()

public Geo::OGR::Feature	GetNextFeature ()

public hash reference	GetSchema ()
	Get the schema of this layer. More...

public Geo::OGR::Geometry	GetSpatialFilter ()

public method	GetStyleTable ()

public method	Identity (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	InsertFeature (scalar feature)

public method	Intersection (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	ReorderField ()

public method	ReorderFields ()

public method	ResetReading ()

public method	RollbackTransaction ()

public hash reference	Row (hash row)

public method	SetAttributeFilter (scalar filter_string)

public method	SetFeature (scalar feature)

public method	SetIgnoredFields (array fields)

public method	SetNextByIndex (scalar new_index)

public method	SetSpatialFilter (scalar filter)

public method	SetSpatialFilterRect (scalar minx, scalar miny, scalar maxx, scalar maxy)

public method	SetStyleTable ()

public Geo::OGR::Geometry	SpatialFilter (array filter)

public Geo::OSR::SpatialReference	SpatialReference (scalar name, Geo::OSR::SpatialReference sr)

public method	StartTransaction ()

public method	SymDifference (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	SyncToDisk ()

public scalar	TestCapability (scalar cap)

public list	Tuple (array tuple)

public method	Union (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

public method	Update (Geo::OGR::Layer method, Geo::OGR::Layer result, hashref options, coderef callback, scalar callback_data)

Public Member Functions inherited from Geo::GDAL::MajorObject
public scalar	Description (scalar description)

public method	Domains ()

public scalar	GetDescription ()

public hash reference	GetMetadata (scalar domain="")

public method	GetMetadataDomainList ()

public hash reference	Metadata (hashref metadata=undef, scalar domain= '')

public method	SetDescription (scalar NewDesc)

public method	SetMetadata (hashref metadata, scalar domain="")

Public Member Functions inherited from Geo::GDAL
public method	BuildVRT ()

public method	CPLBinaryToHex ()

public method	CPLHexToBinary ()

public method	CreatePansharpenedVRT ()

public scalar	DataTypeIsComplex (scalar DataType)

public list	DataTypeValueRange (scalar DataType)

public list	DataTypes ()

public scalar	DecToDMS (scalar angle, scalar axis, scalar precision=2)

public scalar	DecToPackedDMS (scalar dec)

public method	DontUseExceptions ()

public Geo::GDAL::Driver	Driver (scalar Name)

public list	DriverNames ()

public list	Drivers ()

public method	EscapeString ()

public scalar	FindFile (scalar basename)

public method	FinderClean ()

public method	GOA2GetAccessToken ()

public method	GOA2GetAuthorizationURL ()

public method	GOA2GetRefreshToken ()

public scalar	GetCacheMax ()

public scalar	GetCacheUsed ()

public scalar	GetConfigOption (scalar key)

public scalar	GetDataTypeSize (scalar DataType)

public method	GetJPEG2000StructureAsString ()

public Geo::GDAL::Driver	IdentifyDriver (scalar path, scalar siblings)

public Geo::GDAL::Dataset	Open (hash params)

public Geo::GDAL::Dataset	OpenEx (hash params)

public list	OpenFlags ()

public Geo::GDAL::Dataset	OpenShared (scalar name, scalar access= 'ReadOnly')

public scalar	PackCharacter (scalar DataType)

public scalar	PackedDMSToDec (scalar packed)

public method	PopFinderLocation ()

public method	PushFinderLocation (scalar path)

public list	RIOResamplingTypes ()

public list	ResamplingTypes ()

public method	SetCacheMax (scalar Bytes)

public method	SetConfigOption (scalar key, scalar value)

public method	UseExceptions ()

public method	VSIFOpenExL ()

public method	VSIGetLastErrorMsg ()

public method	VSIGetLastErrorNo ()

public scalar	VersionInfo (scalar request= 'VERSION_NUM')

public scalar	errstr ()

Public Member Functions inherited from Geo::OGR
public list	ByteOrders ()

public Geo::GDAL::Driver	Driver (scalar name)

public list	DriverNames ()

public list	Drivers ()

public scalar	GeometryTypeModify (scalar type, scalar modifier)

public scalar	GeometryTypeTest (scalar type, scalar test, scalar type2)

public list	GeometryTypes ()

public method	GetNonLinearGeometriesEnabledFlag ()

public method	GetOpenDSCount ()

public Geo::GDAL::Dataset	Open (scalar name, scalar update=0)

public Geo::GDAL::Dataset	OpenShared (scalar name, scalar update=0)

public method	SetGenerate_DB2_V72_BYTE_ORDER (scalar Generate_DB2_V72_BYTE_ORDER)

public method	SetNonLinearGeometriesEnabledFlag ()

Detailed Description

A collection of similar features.

A layer object is typically obtained with a data source object. A layer has a data model (a schema), which is maintained in a definition object, and a set of features, which contain data according to the data model. The schema is typically set when the layer is created or opened, but it may be altered somewhat with methods Geo::OGR::Layer::CreateField, Geo::OGR::Layer::AlterFieldDefn, and Geo::OGR::Layer::DeleteField. Features and/or their data can be read, inserted and deleted. Reading can be filtered. Layers can be compared to each other with methods Clip, Erase, Identity, Intersection, SymDifference, Union, and Update.

A layer may have metadata OLMD_FID64 => 'YES' if it holds features with 64 bit FIDs. The metadata of a layer can be obtained with GetMetadata method.

Definition at line 12367 of file all.pm.

Member Function Documentation

public method Geo::OGR::Layer::AlterFieldDefn	(	scalar	name,
		hash	params
	)

Object method.

Parameters

field	the name of the field to be altered.
params	as in Geo::OGR::FieldDefn::new. Width and Precision should be both or neither.

Note: Only non-spatial fields can be altered.; Also the deprecated form AlterFieldDefn($field, Geo::OGR::FieldDefn $Defn, $Flags) works.

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public list Geo::OGR::Layer::Capabilities ( )

Object method. Both a package subroutine and an object method.

Returns: a list of capabilities. The object method returns a list of the capabilities the layer has. The package subroutine returns a list of all potential capabilities a layer may have. These are currently: AlterFieldDefn, CreateField, CreateGeomField, CurveGeometries, DeleteFeature, DeleteField, FastFeatureCount, FastGetExtent, FastSetNextByIndex, FastSpatialFilter, IgnoreFields, MeasuredGeometries, RandomRead, RandomWrite, ReorderFields, SequentialWrite, StringsAsUTF8, and Transactions.

Examples:

@cap = Geo::OGR::Layer::Capabilities(); # the package subroutine

@cap = $layer->Capabilities(); # the object method

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public method Geo::OGR::Layer::Clip	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. Clip off areas that are not covered by the method layer. The schema of the result layer can be set before calling this method, or is initialized to to contain all fields from this and method layer.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::CommitTransaction ( )

Object method.

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public method Geo::OGR::Layer::CreateFeature ( scalar feature )

Object method.

Deprecated:: use Geo::OGR::Layer::InsertFeature which accepts Perl data and checks for geometry type and attribute data

Note: The feature should have the same schema as the layer.

Inserts a feature into the layer. The given feature's id may change.

Parameters

feature a Geo::OGR::Feature object

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public method Geo::OGR::Layer::CreateField ( hash params )

Object method. Create a field.

Parameters

params as in Geo::OGR::FieldDefn::new or Geo::OGR::GeomFieldDefn::new, plus ApproxOK (whose default is true).

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public method Geo::OGR::Layer::Dataset ( )

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public method Geo::OGR::Layer::DataSource ( )

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public method Geo::OGR::Layer::DeleteFeature ( scalar fid )

Object method.

Parameters

fid	feature id

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public method Geo::OGR::Layer::DeleteField ( scalar field )

Object method. Delete an existing field from a layer.

Parameters

field name (or index) of the field which is deleted

Note: Only non-spatial fields can be deleted.

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public method Geo::OGR::Layer::Erase	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are in the input layer but not in the method layer. The features in the result layer have attributes from the input layer. The schema of the result layer can be set by the user or, if it is empty, is initialized to contain all fields in the input layer.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::ForFeatures	(	scalar	code,
		scalar	in_place
	)

Object method.

Note: experimental, the syntax may change

Call code for all features. This is a simple wrapper for ResetReading and while(GetNextFeature).

Example usage:

$layer->ForFeatures(sub {my $f = shift; $self->DeleteFeature($f->FID)}); # empties the layer

Parameters

code	a reference to a subroutine, which is called with each feature as an argument
in_place	if set to true, the feature is stored back to the layer

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public method Geo::OGR::Layer::ForGeometries	(	scalar	code,
		scalar	in_place
	)

Object method.

Note: experimental, the syntax may change

Call code for all geometries. This is a simple wrapper for ResetReading and while(GetNextFeature).

Example usage:

my $area = 0;

$layer->ForGeometries(sub {my $g = shift; $area += $g->Area}); # computes the total area

Parameters

code	a reference to a subroutine, which is called with each geometry as an argument
in_place	if set to true, the geometry is stored back to the layer

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public scalar Geo::OGR::Layer::GeometryType ( scalar field )

Object method.

Parameters

field the name or index of the spatial field.

Returns: the geometry type of the spatial field.

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public Geo::OGR::DataSource Geo::OGR::Layer::GetDataSource ( )

Object method.

Returns: the data source object to which this layer object belongs to.

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public Geo::OGR::FeatureDefn Geo::OGR::Layer::GetDefn ( )

Object method. A.k.a GetLayerDefn.

Returns: a Geo::OGR::FeatureDefn object.

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public list Geo::OGR::Layer::GetExtent ( scalar force = 1 )

Object method.

Parameters

force compute the extent even if it is expensive

Note: In scalar context returns a reference to an anonymous array containing the extent.

Returns: the extent ($minx, $maxx, $miny, $maxy)

Parameters

force

Returns: the extent = ($minx, $maxx, $miny, $maxy) as a listref

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public Geo::OGR::Feature Geo::OGR::Layer::GetFeature ( scalar fid )

Object method.

Parameters

fid	feature id

Returns: a new Geo::OGR::Feature object that represents the feature in the layer.

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public scalar Geo::OGR::Layer::GetFeatureCount ( scalar force = 1 )

Object method.

Parameters

force

Returns: integer

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public scalar Geo::OGR::Layer::GetFeaturesRead ( )

Object method.

Returns: integer

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public scalar Geo::OGR::Layer::GetFIDColumn ( )

Object method.

Returns: the name of the underlying database column being used as the FID column, or "" if not supported.

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public hash Geo::OGR::Layer::GetFieldDefn ( scalar name )

Object method. Get the definition of a field.

Parameters

name	the name of the field.

Returns: the field definition object, either Geo::OGR::FieldDefn or Geo::OGR::GeomFieldDefn.

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public list Geo::OGR::Layer::GetFieldNames ( )

Object method.

Returns: a list of the names of the fields in this layer. The non-geometry field names are first in the list and then the geometry fields.

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public scalar Geo::OGR::Layer::GetName ( )

Object method.

Returns: the name of the layer.

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public Geo::OGR::Feature Geo::OGR::Layer::GetNextFeature ( )

Object method.

Returns: iteratively Geo::OGR::Feature objects from the layer. The iteration obeys the spatial and the attribute filter.

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public hash reference Geo::OGR::Layer::GetSchema ( )

Get the schema of this layer.

Object method.

Note: The schema of a layer cannot be set with this method. If you have a Geo::OGR::FeatureDefn object before creating the layer, use its schema in the Geo::OGR::CreateLayer method.

Returns: the schema of this layer, as in Geo::OGR::FeatureDefn::Schema.

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public Geo::OGR::Geometry Geo::OGR::Layer::GetSpatialFilter ( )

Object method.

Returns: a new Geo::OGR::Geometry object

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public method Geo::OGR::Layer::GetStyleTable ( )

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public method Geo::OGR::Layer::Identity	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are in the input layer. The features in the result layer have attributes from both input and method layers. The schema of the result layer can be set by the user or, if it is empty, is initialized to contain all fields in input and method layers.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::InsertFeature ( scalar feature )

Object method. Creates a new feature which has the schema of the layer and initializes it with data from the argument. Then inserts the feature into the layer (using CreateFeature). Uses Geo::OGR::Feature::Row or Geo::OGR::Feature::Tuple.

Parameters

feature a Geo::OGR::Feature object or reference to feature data in a hash (as in Geo::OGR::Feature::Row) or in an array (as in Geo::OGR::Feature::Tuple)

Returns: the new feature.

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public method Geo::OGR::Layer::Intersection	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are common between features in the input layer and in the method layer. The schema of the result layer can be set before calling this method, or is initialized to contain all fields from this and method layer.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::ReorderField ( )

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public method Geo::OGR::Layer::ReorderFields ( )

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public method Geo::OGR::Layer::ResetReading ( )

Object method. Initialize the layer object for iterative reading.

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public method Geo::OGR::Layer::RollbackTransaction ( )

Object method.

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public hash reference Geo::OGR::Layer::Row ( hash row )

Object method. Get and/or set the data of a feature that has the supplied feature id (the next feature obtained with GetNextFeature is used if feature id is not given). Calls Geo::OGR::Feature::Row.

Parameters

row	[optional] feature data

Returns: a reference to feature data in a hash

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public method Geo::OGR::Layer::SetAttributeFilter ( scalar filter_string )

Object method. Set or clear the attribute filter.

Parameters

filter_string a SQL WHERE clause or undef to clear the filter.

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public method Geo::OGR::Layer::SetFeature ( scalar feature )

Object method.

Note: The feature should have the same schema as the layer.

Replaces a feature in the layer based on the given feature's id. Requires RandomWrite capability.

Parameters

feature a Geo::OGR::Feature object

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public method Geo::OGR::Layer::SetIgnoredFields ( array fields )

Object method.

Parameters

fields a list of field names

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public method Geo::OGR::Layer::SetNextByIndex ( scalar new_index )

Object method.

Parameters

new_index the index to which set the read cursor in the current iteration

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public method Geo::OGR::Layer::SetSpatialFilter ( scalar filter )

Object method.

Parameters

filter [optional] a Geo::OGR::Geometry object. If not given, removes the filter if there is one.

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public method Geo::OGR::Layer::SetSpatialFilterRect	(	scalar	minx,
		scalar	miny,
		scalar	maxx,
		scalar	maxy
	)

Object method.

Parameters

minx
miny
maxx
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public method Geo::OGR::Layer::SetStyleTable ( )

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public Geo::OGR::Geometry Geo::OGR::Layer::SpatialFilter ( array filter )

Object method.

Parameters

filter [optional] a Geo::OGR::Geometry object or a string. An undefined value removes the filter if there is one.

Returns: a new Geo::OGR::Geometry object

Parameters

filter [optional] a rectangle ($minx, $miny, $maxx, $maxy).

Returns: a new Geo::OGR::Geometry object

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public Geo::OSR::SpatialReference Geo::OGR::Layer::SpatialReference	(	scalar	name,
		Geo::OSR::SpatialReference	sr
	)

Object method.

Note: A.k.a GetSpatialRef. Get or set the projection of a spatial field of this layer. Gets or sets the projection of the first field if no field name is given.

Parameters

name	[optional] a name of a spatial field in this layer.
sr	[optional] a Geo::OSR::SpatialReference object, which replaces the existing projection.

Returns: a Geo::OSR::SpatialReference object, which represents the projection in the given spatial field.

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public method Geo::OGR::Layer::StartTransaction ( )

Object method.

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public method Geo::OGR::Layer::SymDifference	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are in either in the input layer or in the method layer but not in both. The features in the result layer have attributes from both input and method layers. For features which represent areas that are only in the input or in the method layer the respective attributes have undefined values. The schema of the result layer can be set by the user or, if it is empty, is initialized to contain all fields in the input and method layers.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::SyncToDisk ( )

Object method.

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public scalar Geo::OGR::Layer::TestCapability ( scalar cap )

Object method.

Parameters

cap	A capability string.

Returns: a boolean value indicating whether the layer has the specified capability.

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public list Geo::OGR::Layer::Tuple ( array tuple )

Object method. Get and/set the data of a feature that has the supplied feature id (the next feature obtained with GetNextFeature is used if feature id is not given). The expected data in the tuple is: ([feature id,] non-spatial fields, spatial fields). Calls Geo::OGR::Feature::Tuple.

Parameters

tuple [optional] feature data

Note: The schema of the tuple needs to be the same as that of the layer.

Returns: a reference to feature data in an array

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public method Geo::OGR::Layer::Union	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are in either in the input layer or in the method layer. The schema of the result layer can be set before calling this method, or is initialized to contain all fields from this and method layer.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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public method Geo::OGR::Layer::Update	(	Geo::OGR::Layer	method,
		Geo::OGR::Layer	result,
		hashref	options,
		coderef	callback,
		scalar	callback_data
	)

Object method. The result layer contains features whose geometries represent areas that are either in the input layer or in the method layer. The features in the result layer have areas of the features of the method layer or those ares of the features of the input layer that are not covered by the method layer. The features of the result layer get their attributes from the input layer. The schema of the result layer can be set by the user or, if it is empty, is initialized to contain all fields in the input layer.

Parameters

method	method layer.
result	result layer.
options	a reference to an options hash.
callback	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, callback_data)
callback_data	[optional]

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The documentation for this class was generated from the following file:

all.pm

Public Member Functions

Detailed Description

Member Function Documentation